Ignition distributor

ABSTRACT

An ignition distributor for an internal combustion engine spark ignition system includes a hollow casing closed at one end by a detachable insulating cap. A rotatable shaft is supported by the casing and carries a rotor arm which co-operates with high tension electrodes carried by the cap. Within the enclosure defined by the casing and the cap is an ignition coil including two separable parts. A first part of the coil includes a first core component and the coil primary winding and the second coil part includes a second core component and the coiled secondary winding. The two ignition coil parts are located in position relative to one another to constitute an ignition coil by the distributor cap and the casing.

United States Patent 71191 1,976,178 l/l934 Mallory 123/.148D

Jukes et al. 1451 Mar. 5, 1974 IGNITION DISTRIBUTOR 3,682,098 8/1972 Spies 336/D1G. 2 x

' l, 83,343 12 '1 3l7 [751 Inventors Alfred l walsau; 2,219,513 uii gg v lfcilfenbargcr 12 5 1 42 Dftlfekkfllbefl Gramger, 3,277,358 10/1966 Nicholl 336/DIG. 2 x Klddermmster, t of England 1,826,888 10/1931 Kilponcn 317/I57.6 x

[73] Assignee: Joseph Lucas (Electrical) Limited,

Binningham, England Primary ExaminerTh0mas J. Kozma [22] Filed: Jan. 1973 Attorney, Agent, or Firm-Holman & Stern 1211 Appl. No.: 323,393

' [57] ABSTRACT Foreign Application Priority Data A11 ignition distributor for an internal combustion en- Jan 14 1972 Great Edwin 1834/72 gme spark 1gn1t1on system includes a hollow casmg closed at one end by a detachable insulating cap. A rotatable shaft is supported by the casing and carries a [52] 123/1465 317/1516 rotor arm which co-operates with high tension elec- /96, 336/105, 336/DIG. 2 1

trodes earned by the cap. W1th1n the enclosure de- [51] Int. Cl. F02p 7/00, l-lOlf 17/06 fined by the casing and the cap is an ignition coil [5 8] Field of Search; 336/DIG. 2,105, 96;

123 cludmg two separable parts. A first part of the 0011 1n- /148 D, 148 P, 146.5 A; 317/1516; d d h 315/211 214 c u es a rst core component'an t e CO1 primary wmdmg and the second coll part mcludes a second [56] References Cited 7 core COIIIPQIICHI and the coded secondary wmdmg. v The two 1gn1t1on COll parts are located in pos1t1on rela- UNITED STATES PATENTS tive to one another to constitute an ignition coil by the 2,161,043 6/1939 Heintzu'l 123/148 D distributor cap and the casing. 3,638,630 2/1972 Hetzler et al. l23/l48 D 10 Claims, 2 Drawing Figures PATENTEDHAR Sign 3.795.236

FIG]

V 1 IGNITION DISTRIBUTOR This invention relates to an ignition distributor for an internal combustionengine spark ignition system.

An ignition distributor according to the invention in-' eludes a hollow casing closed at one end by a detachable insulating cap, a rotatable shaft supported by the casing and carrying a rotor arm co-operable with high tension electrodes carried by the cap, and, an ignition coil, the coil having two separable parts, a first part including a first core component and the coil primary winding and a second part including a second core component and the coil secondary winding, the two parts being located in position relative to one another to constitute an ignition coil, by the distributor cap and easing.

Preferably the first ignition coil part is positioned within the casing and the second coil part is positioned within the cap.

Desirably the first and second core components are such that in use they define a rectangular iron circuit.

Preferably the two core componentsare each substantially U-shaped having their respective windings encircling their bases. i

Conveniently each coil part is encapsulated in synthetic resin material with the exception of those regions of their core components which are to be presented to the other core component. f

Preferably the first coil part is detachably secured to the distributor casing and the second coil partflis'detachably securedto the distributor cap.

Conveniently one end of the. secondary winding is electrically connected to a high tension input electrode on the cap by way of a lead located by the cap.

Desirably the other end of the secondary winding is electrically connected to its respective core component and the first core component is earthed in use through the casing of the distributor.

Conveniently one end of the primary winding is con nected to a low tension input terminal accessible from the exterior of the casing and the other end of the winding is connected within the casing, to the contact breaker of the ignition distributor.

Desirably the first and second core components are spaced apart by non-magnetic spacer means. Preferably the spacer means electrically interconnects the core components. v

encircling the shaft 15 is a contact breaker assembly including a fixed electrical contact and a movable electrical contact. The movable contact is carried by a pivoted heel member engageable with the cam shaft, and rotation of the cam shaft causes movement of the heel member to make and break the fixed and movable contacts in the usual manner.

The casing 11 is extended at 11a to define a pocket 18 within which is'housed a first ignition coil part 19. The ignition coil part 19 comprises a core component 21 of laminated construction, and of generally U- shaped form. Wound around the base of the U-shaped core component 21 is a primary winding 22 and the assembly of the component 21 and winding 22 is encapsulated in synthetic resin material within the pocket 18. A plurality of self-tapping screws extend through the casing wall and into the synthetic resin encapsulation, and thereby serve to retain the first coil part within the pocket 18. It will be appreciated that by removing the screws in the normal manner the encapsulated first coil part can be removed from the pocket 18, the pocket 18 tapering inwardly from its open end to facilitate.removal of the first coil part. The limbs of the core part are not within the encapsulation and are received in recesses in the wall of the pocket 18..

The cap 12 of the ignition distributor has an extension 12a equivalent to the extension 11a of the casing 11. There is no internal dividing wall within the cap 12 to define a pocket, but within the extension 12a is posi-- tioned a second ignition coil part 23. The second coil part 23 comprises a core component 24 substantially identical to the first core component 21. Wound around the base ,of the core-component 24 isan ignition coil secondary winding 25 and the core component and secondary winding 25 are encapsulated in synthetic resin material. The encapsulated unit constitutingthe second coil part is similarly secured within'the cap 12 One example of the invention is'illu strated in the ac- Referring to the drawings, the ignition distributor in,- cludes a hollow casing 11 an open end of which is closed by an insulating cap 12. The cap 12 carries a high tension input electrode 13 and a pluralityof high tension output terminals 14 spaced around the input terminal 13. The terminal 13 is aligned with the axis of an engine driven shaft 15 which is rotatably supported within the casing, and which carries a cam shaft in turn supporting a rotor arm 16. The cam shaft and, the rotor arm 16 rotate with the shaft 15 about the axis thereof and the terminal 13 bears against the conductor 16 of the rotor arm 16. As the rotor arm 16 rotates the conductor 17 passes in turn adjacent the output electrodes 14 in the usual manner. Positionedwithin the casing by self-tapping screws. Again the projecting limbs of the core part are received in recesses in the wall of the cap and the inner surfaces of the cap taper to facilitate removal of the second coil part. I Conveniently, the unencapsulated coil parts can be positioned within their respective ignition distributor parts which can then be used as moulds for the encapsulating material. The self-tapping screws being placed in position prior to insertion of the encapsulating material. The freeends of the limbs of the core components which are, in use, presented towards one another are not encapsulated. a The core components 21, 24 define in use, a iron circuit and in order to ensure that the transformer produced by the two coil componentsis.satisfactory for use as an ignition coil, an air gap is introducedinto the iron circuit. Thus the ends of the limbs of the core component 21 are spaced from the ends of the limbs of the core component-24 by respective non-magnetic spacers 26. The spacers 26 are preferably formed from electrically conductive material, for example, brass so that the two core components are electrically interconnected in use.

One end of the secondary winding 25 is electrically connected to the core component 24, while the other end of the secondary winding is electrically connected to the electrode 13. The secondary winding 25 is electrically connected to the electrode 13 by way of alead or air gap then a separate electrical connection between the core components would be provided. Alternatively, the secondary winding could be earthed by a different route. One end of the primary winding 22 is electrically connected to a terminal 29 accessible from the exterior of the casing 11. The other end of the primary winding 22 is electricallyconnected by way of a lead 31 to the movable contact of the contact breaker assembly, the fixed contact of the contact breaker'assembly being earthed through the casing 11. The terminal 29 constitutes the low tension input terminal of the arrangement and as the current flowing-in the primary winding 22 is interrupted by operation of the contact breaker assembly high tension sparking pulses are generated in the secondary winding 25 and applied by way of the lead 27, the electrode 13, the rotor arm 16 and the electrodes 14 to the sparking plugs of the associated internal combustion engine in turn.

It will be appreciated, that provided electrically conductive spacers 26 are utilized then the electrical connections required within the ignition coil will be made automatically as the cap 12 is engaged with the casing 11. However, the ignition coil is in the form of two separable units, and either can be replaced independently of the other where necessary. Moreover, since the coil parts are detachable from their respective carriers then should for example the cap 12 require replacement then the coil part can be removed and utilized in the replacement cap. The cap is attached to the casing in the conventional manner by spring clips, or captive screws.

The spacers 26 are conveniently in the form of ribbed, or bowed pieces of brass strip, the ribs, or the bowing being chosen so that they deform when the cap and casing are interengaged, to provide the desired air gap in the magnetic core circuit. Additionally, owing to their inherent resilience the spacers, when deformed, act as springs taking up any play'between the cap and the casing, and ensuring a good electrical connection between the core components. Where the spacer is a radio frequency suppression capacitor which may be provided, can be encapsulated in the encapsulation of one or other of the coil parts.

In the arrangement described above the shaft 15 carries a cam shaft, and the casing houses a contact breaker assembly operated by the cam shaft. It is to be appreciated that the shaft 15 could drive any alternative device whereby the circuit of the primary winding of the ignition, coil can be made and broken in timed relation to the operation of the engine. For example a' magnetic device rotated by the shaft 15 could operate with a magnetic pick-up controlling the coil primary circuit.

We claim: I

1. An ignition distributor including a hollow casing closed at one end by a detachable insulating cap, a rotatable-shaft supported by the casing and carrying a rotor arm co-operable with high tension electrodes carried by the cap, and, an ignition coil, the coil having two separable parts, a first part including a first core component and the coil primary winding and a second part including a second core component and the coil secondary winding, wherein the first ignition coil part is positioned within the casing and the second coil part is positioned within the cap. a

2. A distributor as claimed in claim 1 wherein first and second core components are such that in use they define a rectangular iron circuit.

3. A distributor as claimed in claim 1' wherein the two core components are each substantially U-shaped having their respective windings encirclingtheir bases' 4. A distributor as claimed in claim 1 wherein each coil part is encapsulated in synthetic resin material with the exception of those regions of their core components which are to be presented to the other core component. i l

5. .A 'dist'ributor'as claimed in claim '1 wherein the first coil part is detachably secured to the distributor casing and the second coil'part is detachably secured to the distributor cap.

6. A distributor as claimed in claim 1 wherein one end of the secondary winding is electrically connected to a high tension input electrode on the cap by way of a lead located by the cap. a

7. A distributor as claimed in claim 6 wherein the other end of the secondary winding is electrically connected to its respective core component and the first corecomponent is earthed in use through the casing of the distributor.

8. A distributor as claimed in claim- 1 wherein one end of the primary winding is connected to a low tension input terminal accessible from the exterior of the casing and the other end of the winding is connected within the casing, to the contact breaker of the ignition distributor; a

9. A distributor as claimed i n claim ,1 wherein the first and second core componentsarc spaced apart by non-magnetic spacer means. a

10. A distributor as claimed in claim 9 wherein the spacer means electrically interconnects thecore components. 

1. An ignition distributor including a hollow casing closed at one end by a detachable insulating cap, a rotatable shaft supported by the casing and carrying a rotor arm co-operable with High tension electrodes carried by the cap, and, an ignition coil, the coil having two separable parts, a first part including a first core component and the coil primary winding and a second part including a second core component and the coil secondary winding, wherein the first ignition coil part is positioned within the casing and the second coil part is positioned within the cap.
 2. A distributor as claimed in claim 1 wherein first and second core components are such that in use they define a rectangular iron circuit.
 3. A distributor as claimed in claim 1 wherein the two core components are each substantially U-shaped having their respective windings encircling their bases.
 4. A distributor as claimed in claim 1 wherein each coil part is encapsulated in synthetic resin material with the exception of those regions of their core components which are to be presented to the other core component.
 5. A distributor as claimed in claim 1 wherein the first coil part is detachably secured to the distributor casing and the second coil part is detachably secured to the distributor cap.
 6. A distributor as claimed in claim 1 wherein one end of the secondary winding is electrically connected to a high tension input electrode on the cap by way of a lead located by the cap.
 7. A distributor as claimed in claim 6 wherein the other end of the secondary winding is electrically connected to its respective core component and the first core component is earthed in use through the casing of the distributor.
 8. A distributor as claimed in claim 1 wherein one end of the primary winding is connected to a low tension input terminal accessible from the exterior of the casing and the other end of the winding is connected within the casing, to the contact breaker of the ignition distributor.
 9. A distributor as claimed in claim 1 wherein the first and second core components are spaced apart by non-magnetic spacer means.
 10. A distributor as claimed in claim 9 wherein the spacer means electrically interconnects the core components. 